#include <stdio.h>

#define PI 3.1415926535799323

int main(){
	//double pi = 3.14;
	int r = 4;
	double c = 2 * PI * r;
	double s = PI * r * r;
	printf("周长为%lf面积为%lf\n",c,s);
	return 0;
}
